Short trips at low, low rpm could be the issue. I believe the cam shaft, which is iron, is lubed by splash oiling meaning oil flung off of the crank. So low rpms could cause some wear in that respect. If it were me, I'd get an oil with moly... There are quite a few of them out there. Moly clings to metal and sacrifices itself instead of the part. I've got a blackstone report coming in today or tomorrow. I had some copper issues. And a bad turbo. I'll post back with my results and we can compare. :thumbsup